Shun NagaiThe topic of cats and carbohydrates is often debated. It is understandable that many pet owners, looking at the carnivorous habits of wild cats, believe that domestic cats should also eat a high-protein, low-carbohydrate diet.
However, most commercial dry cat foods contain around 40% protein, while the proportion of carbohydrates is often much higher. This naturally raises questions about whether cats actually need carbohydrates and whether they are even capable of digesting them.
If you want to provide your cat with a balanced diet, here is what you should know about carbohydrate content in cat food.
Do Cats Need Carbohydrates?
Many owners assume that because cats are obligate carnivores, there is no need to include carbohydrates in cat food. This idea can be very misleading. In reality, carbohydrates are necessary for all mammals.
During digestion, carbohydrates are broken down into glucose. Glucose provides energy to the body’s cells and supports their daily activity. In that sense, cats do need carbohydrates in their diet.
Cats also rely on the fiber found in carbohydrate-containing ingredients to keep their digestive system functioning properly. Protein does not contain fiber, so completely eliminating carbohydrates may lead to constipation and other digestive problems.
That said, cats require far fewer carbohydrates than many other mammals. Their requirement is significantly lower than that of dogs, but they still need some carbohydrates, and a completely carbohydrate-free diet may not provide enough energy.
The source of carbohydrates also matters. For example, cats do not need to get carbohydrates from grains. They can also obtain carbohydrates from plant-based sources such as vegetables and fruits that contain appropriate levels of vitamins, minerals, and fiber.
The Relationship Between Carbohydrates and Diabetes
Many cat owners worry that feeding too many carbohydrates may increase the risk of diabetes. Because cats are often believed to be unable to digest carbohydrates in the same way as other mammals, some assume that excess carbohydrate intake causes blood sugar spikes and raises the risk of diabetes.
However, one study suggests that the major risk factors for diabetes are indoor living, lack of exercise, and obesity—not necessarily a high-carbohydrate diet. A balanced diet and regular exercise are essential for protecting cats from diabetes.
The Difference Between Wild Cats and Domestic Cats
Domestic cats and wild cats share the same origins, but their diets are very different. Many owners try to feed their cats a diet that seems closer to what wild cats eat by avoiding kibble or canned food and offering fresh food instead. However, this approach may result in insufficient carbohydrate intake.
It is true that wild cats are rarely seen eating vegetables or fruits. But in reality, they still consume carbohydrates. After catching prey, wild cats eat the whole animal, including the stomach contents, which can serve as a source of carbohydrates.
Cheetahs, which are often considered close relatives of domestic cats, may sometimes eat the stomach contents of their prey first. By doing so, they consume plant matter and maintain a more balanced diet.
Domestic cats, however, usually eat canned or dry food rather than live prey. Even if they are fed fresh meat, they are not consuming the entire animal, including the stomach contents. For that reason, domestic cats need to obtain carbohydrates in other ways.
How Do Cats Process Carbohydrates?
In general, the main carbohydrate found in cat food—both wet and dry—is starch, a type of polysaccharide. Therefore, it is helpful to understand how starch is digested and used as energy in a cat’s body.
Starch is naturally difficult for cats to digest. However, when it is heated and gelatinized, it becomes much easier to digest. For example, dry food is processed using extrusion, in which starch is heated to around 100–160°C. This gelatinization makes it easier for the cat’s body to break starch down into glucose.
Once glucose is absorbed into the body, it is transported through the portal vein and distributed throughout the body. Glucose in the bloodstream is known as blood sugar, and it is taken up by cells and used as an energy source.
Too Much Can Be a Problem
Even so, excessive starch intake should be approached with caution in cats. Cats do not have amylase in their saliva, the enzyme that breaks down starch into glucose. In addition, the amount of amylase secreted by the pancreas is also relatively low. As a result, cats are not well equipped to handle large amounts of starch.
What Is the Ideal Carbohydrate Ratio?
Carbohydrates are needed in a cat’s diet, but the amount should be controlled. Some experts recommend a level of 10–15%, which is similar to the amount wild cats are thought to consume. In more practical terms, many believe it is best to keep carbohydrate content below 30%.
| Item | Formula |
|---|---|
| Carbohydrate (%) | 100% – protein – fat – ash – moisture |
In the Case of AAFCO Standards
The Association of American Feed Control Officials (AAFCO) does not require pet food manufacturers to list carbohydrate content, nor does it set a carbohydrate requirement for cat food. However, AAFCO does establish minimum standards for crude protein and crude fat. For adult cats, the recommended minimums are 26% crude protein and 9% crude fat.
AAFCO also provides standards for certain minerals, vitamins, and crude fiber. If these nutrient levels and ratios are met, AAFCO may recognize the food as “complete and balanced,” regardless of its carbohydrate content.
The Importance of a Balanced Diet
For cats to live healthy and happy lives, they need a balanced diet. In the pet food industry, this is often described as “protein-forward,” meaning that protein is the most abundant nutrient in the cat food formula.
However, this does not mean cats should eat a diet made up only of protein. Fresh fish or meat alone may be lacking in important vitamins, minerals, and fiber that cats also need.
A balanced diet helps maintain stable blood sugar levels and supports healthy weight management. It is also important for cats to consume carbohydrates that can contribute to energy production.
Dietary Fiber Provided by Carbohydrates
One reason an extremely low-carbohydrate diet may not be ideal for cats is the lack of dietary fiber. Fiber is usually supplied through carbohydrate-containing ingredients and plays an important role in feline health.
Because cats groom themselves by licking their fur, hairballs can accumulate in the digestive tract. Dietary fiber helps trap these hairballs and supports healthy digestion.
Essential Amino Acids for Cats
When discussing cat food, amino acids cannot be overlooked. Although this is not directly related to carbohydrate intake, amino acids are indispensable organic compounds for cats.
For example, taurine is one of the amino acids that cats must obtain through their diet. Cats cannot produce taurine on their own, so it must come from food. Taurine is found in high-quality meats and plays an essential role in heart function and vision.
Arginine is another amino acid that cats must obtain from their diet. Unlike taurine, cats can produce arginine in the body, but not in sufficient amounts.
Arginine is responsible for helping convert ammonia into urea in the urinary system. If arginine is lacking, ammonia can build up in the blood, strongly affecting the central nervous system and potentially causing impaired consciousness.